It is probably difficult to generalize an answer to this question, but…
What’s a good rule-of-thumb regarding the loss of glide that one experiences with a skeg dropped?
Maybe a better way to phrase this would be to get specific. Assume a CD Gulfstream, smooth water, no wind, reasonably efficient paddling stroke, no hangover. What’s the penalty to be paid for dropping the skeg over, say, 5 miles? And I assume that there is less drag from the skeg if it’s only dropped, say, halfway?
Thanks very much,
It is probably difficult to generalize an answer to this question, but…
Would you drop it in those conditions?
The boat will tell you when to use half/full..
A GPS will tell you what the loss/gain might be.
When you need the skeg it should increase your speed..
OK, I'll take the GPS with me in the morning and give you a percentage, my Caribou has the same skeg..
I have been paddling my Gulfstream
for 4 years.
There is absolutely no reason to drop the skeg except to correct weathercocking from winds. If the wind is strong enough to cause you to weathercock, the skeg will improve your speed by eliminating the need to do corrective strokes or paddle on edge.
If you are having a problem paddling straight without the skeg in conditions without wind, work on your forward stroke. The skeg will not help correct this and the drag will actually hinder your performance.
Your sort of looking at it the wrong way.
It the skeg is costing you speed - you shouldn’t be using the skeg.
If conditions warrant using some degree of skeg - the aid it provides in holding course at an angle to wind/waves will allow more concentration on forward stroke and less on corrective - and speed will be better with the skeg than without.
Same thing regarding how much skeg to use. Just enough to balance the hull and minimize need for corrective strokes. More OR less than needed will slow you down.
Skeg can be adjusted fine by feel, but a GPS can make this speed issue more clear over time, and makes it easier to fine tune a bit better than just going by feel. (I’d say Speedmate as well as GPS - but if you’ve got a Speedmate - you’re more likely to have a rudder than a skeg!)
no skeg on my boat now
but i can feel that the stern is wagging some behind my not so perfect strokes. i think a skeg might help efficiency by helping the boat track better. i have read that racers use rudders partly to generate ‘lift’, maybe a similar concept?
Skegs do not make you track better
They are located just behind the cockpit, not at the stern like a rudder.
They are designed to keep the stern from blowing downwind in a cross wind. If you need help getting your boat to track better, either improve your stroke and/or get a boat that tracks.
Or buy a boat with a rudder and say the hell with technique and use it to correct your poor paddling.
Hey, wait a minute
I don’t think the guy said he’s using his skeg for calm-water tracking or asked for advice about that. He asked how much drag a deployed skeg adds and gave a hypothetical situation to try to isolate the effect of skeg drag from other factors that would affect speed. That question can be answered (though not by me) without bashing his skills, about which he said nothing.
The reply was to the poster immediately
above and he said:
“but i can feel that the stern is wagging some behind my not so perfect strokes. i think a skeg might help efficiency by helping the boat track better.”
All of the previous posts, by people who are experienced with skegs, already said they don’t help efficiency in conditions where the boat is not weathercocking.
He said “He THINKS a skeg might help efficiency” while the other posters basically said they know from experience that it doesn’t in conditions without wind.
On my QCC I can’t even tell when the skeg is down except when I try to change headings!! Then yeah I know it immediately.
Unless you’re talking about this specific boat, I have to disagree.
On my glass P&H Capella the skeg is pretty far back on the boat. Certainly not “just behind the cockpit.”
What’s more, it DOES help immensely with tracking when I allow novice paddlers time in my boat.
Heck, back when I bought the boat I was a novice paddler too… every time I took the boat out, I’d spend 30 minutes or so working on my forward stroke (and going in circles) and then I’d drop the skeg, straighten out and enjoy the scenery. This was in no-wind, flat-water conditions.
Nowadays, sure, I only use the skeg in windy conditions… but it took a year of paddling to get here.
You got it right.
Sometimes a question is just ... a question.
Same old board. Back to lurking for another year.
I have a Gulfstream and have to use the skeg at all times. Any conditions even dead flat calm days. If I don’t it just wonders everywhere and does not track straight at all. Biggest problem is it is way to much volume for my weight around the cockpit area and the hull sits to high in the water for me. But usually I only have the skeg 1/2 way down.
So if you have tracking troubles without skeg down it may be the boat isn’t a good fit.
My skeg test results…
The original post intrigued me as to what effect the skeg may have on speed…
I took out my CD Caribou this morning just to see. The Bou is a strong point A to point B tracker so my results may vary. Tested in the open ocean with 12 to 16Kts wind and 1’ or less chop and no white caps yet. I tried to keep my paddling effort uniform and hold a constant heading…
In the lighter wind, about 45* off wind direction there was about a 10 to 15% increase in speed with the skeg deployed. As the wind and seas increased the need for a skeg greatly decreased (a little quirk of the Bou’s bow design.)
Down wind with the skeg gave me about a 5 to 8% increase in speed.
Using the skeg when not needed:
Less than 5% decrease in speed sometimes not very noticeable…
Seeing a double rainbow… PRICELESS…
If you’re searching for tiny amounts of drag, the gap between the skeg and the skeg box is one source. Sealing the gap(rubber strips?) would help. Small sailboat racers are fanatical about reducing play in the centerboard and gaps in the centerboard trunk. Of course, it’s more likely to jam up, but that’s the tradeoff you make.
Also see if if the skeg itself is nicely shaped and finished – many aren’t.
Hardly noticeable - but GPS don’t lie
I can agree that the feel on the 700 is as if there is no drag (and that if I forget to bring it up after a downwind leg it certainly will remind you if you want to turn quickly!).
It does add drag though. Just having the slot back there adds drag. In flat conditions it knocks off a good bit off speed if dropped fully. Anywhere from .2 to .5 mph. (depending on your cruising speed - I', talking ranges like 5-6 mph without, 4.8-5.5 mph with based on my paddling).
The speed gain it provides in quartering/cross/tail winds are similar. Running down wind/rear quartering in chop the skeg can add .5 mph I'd have otherwise lost to corrective strokes.
The SealLine blade on my Q700 is efficient enough, but the turbulence around the aft end of the hull where the water interacts with the slot and intersection of the blade and hull have an effect. With the SealLine blade, sometimes I think full skeg has more drag not so much because more blade is in the water, but because more slot is open.
Overall, this is @ 5-8% speed change (minus in calm, plus in wind)- and matches with what Grayhwk reports (his skeg in more tiangular - so fills the box more when dpeloyed and does not extend as deep - advantages that equal out the SealLIne foils IMO).
the Tempest I found that the standard Tempest skeg, fully deployed, lowered my flatwater, no wind cruising speed by 1 to 2 tenths of a knot.
I experimented with different sized and positioned skegs and ended up with what you see. Needless to say, as the skeg blade grew, the downwind performance increased and acceleration and glide went down. Acceleration is a biggy for me (and the T) as it is what gets you on a swell/wave and allows for surfin’ FUN! One skeg proto I tested held the boat on a very straight, dw course BUT dropped my speed by .5 knot! ouch!
steve (who spent yesterday surfin’ my 165 in the gorge w/ skeg)